Dashboard Warning Lights Guide
Complete guide to understanding dashboard warning lights. Learn what each light means, what action to take, and when to see a mechanic.
Understanding Your Dashboard
Modern cars have dozens of warning lights. Some are informational, some require attention, and others mean you should stop driving immediately.
🔴 Critical Red Warning Lights - Stop Immediately
🛑 Brake Warning Light
What it means: Low brake fluid, handbrake on, or brake system fault
What to do: Check handbrake is fully released. If light stays on, STOP driving immediately. Check brake fluid level. If low or light persists, call for breakdown assistance.
⚠️ DO NOT drive with this light on (except to pull over safely)
🌡️ Engine Temperature Warning
What it means: Engine is overheating - coolant too hot
What to do: Stop as soon as safe. Turn off engine and wait 30 minutes to cool. Check coolant level when cool. If coolant is full and light returns, call for help - don't drive.
⚠️ Driving with an overheating engine can cause catastrophic engine damage
🛢️ Oil Pressure Warning
What it means: Low oil pressure - engine not being lubricated properly
What to do: Stop immediately when safe. Turn off engine. Check oil level. Top up if low. If light stays on after topping up, DO NOT drive - call for recovery.
⚠️ Running with low oil pressure can seize the engine in minutes
⚡ Battery/Charging Warning
What it means: Battery not charging - alternator fault or drive belt broken
What to do: Turn off unnecessary electrics (radio, heater, etc.). Drive to nearest garage or home. Engine will stop when battery dies (usually 30-60 mins).
⚠️ You have limited time before the battery dies and engine stops
🔧 Engine Warning Light (Red)
What it means: Serious engine fault detected
What to do: Stop as soon as safely possible. If the light is flashing, this indicates a serious misfire - stop immediately. Call for assistance.
🟡 Amber/Yellow Warning Lights - Check Soon
| Light | What It Means | What To Do |
|---|---|---|
| 🔧 Engine Warning (Amber) | Emissions fault or sensor issue | Can usually drive, but book garage soon. May affect MOT |
| ⚠️ ABS Warning | ABS system fault | Normal brakes still work, but no ABS. Drive carefully, see mechanic |
| 🔄 ESP/Traction Control | Stability control active or fault | If flashing: system working. If constant: fault - see garage |
| ⚠️ Tyre Pressure (TPMS) | Low tyre pressure | Check and adjust all tyre pressures. Reset if needed |
| 💨 DPF Warning | Diesel Particulate Filter needs regeneration | Drive on motorway for 15 mins at 40+ mph. See manual |
| 🔑 Power Steering | Power steering fault | Steering will be very heavy. Safe to drive slowly to garage |
| 💡 Bulb Warning | Exterior light bulb blown | Check all lights. Replace bulb - illegal to drive with failed lights |
| 💧 Washer Fluid | Windscreen washer fluid low | Top up washer fluid reservoir |
| 🛠️ Service Warning | Service due soon | Book your car in for a service |
🟢 Green/Blue Lights - Information
These lights indicate a system is active - not a fault:
Normal Operation Lights:
- • Side lights: Side/parking lights on
- • Dipped headlights: Headlights on
- • Main beam: Full beam headlights on (blue)
- • Front fog lights: Front fog lights active
- • Rear fog lights: Rear fog lights on (amber)
- • Indicators: Turn signals active (green arrows)
System Active Lights:
- • Cruise control: Cruise control activated
- • Lane assist: Lane keeping system active
- • Eco mode: Economy driving mode on
- • Sport mode: Sport driving mode active
- • DRL: Daytime running lights on
What To Do When a Warning Light Comes On
Step 1: Identify the Light
Check your owner's manual for the specific meaning of the light in your car. Different manufacturers use slightly different symbols.
Step 2: Assess the Color
- Red: Stop as soon as safe
- Amber/Yellow: Check soon, but usually safe to continue
- Green/Blue: Information only
Step 3: Take Appropriate Action
Follow the guidance for that specific light. Some can be resolved yourself (topping up washer fluid), others need immediate professional attention.
Step 4: Log It
Keep a record of when warning lights appear, even if they go off. This can help diagnose intermittent faults.
Common Questions
Can I drive with the engine warning light on?
If it's amber and steady, you can usually drive but book a garage appointment soon. If it's red or flashing, stop immediately.
Will my car pass MOT with a warning light on?
No. Any warning light relating to safety systems (engine, brakes, ABS, airbag, etc.) will cause an MOT failure. Get it checked before your MOT.
Why did my warning light come on then go off?
This could be an intermittent fault. The car's computer stores fault codes even after the light goes off. Get it checked - the problem may return.
How do I reset a warning light?
Fix the underlying problem first! Most warning lights will reset themselves once the issue is resolved. Some (like service lights) can be reset manually - check your handbook.
Track Warning Lights & Repairs
Log warning lights, repairs, and all maintenance in AutoChain. Build a complete record of your car's health.